LS3 Manual Trans Camaro Boosted PE Delay causing lean/knock during Shift

[10_SS]

As the title says, I just installed a Whipple on an otherwise stock LS3 manual trans 2010 Camaro.

And, Im analyzing the logs, and noticed a somewhat serious problem during shifts related to the reaction of the MAP sensor and it delaying PE mode/additional fuel.

Attached is a picture, but what happens is if I shift, then go WOT quickly, then the Airflow spikes up instantly which is good, but the MAP sensor reaction time is slower, and even after it enables PE fueling, there is a delay before injector pulsewidths react... this causes a delay in PE fuel, which then causes lean fueling and lots of knock.

This all happens very fast, the delay looks like about 0.25 seconds long, but is enough time to run lean and cause knock, which is very bad for stock pistons.

My last car was pure SD mode, 1996 TA with procharger 100% reliant off the MAP sensor for fueling and never had this problem as it reacted very fast.

Is there some type of smoothing or delay built into the MAP sensor reading, or something else I can do to speed up it's response time? The MAF sensor reacts instantly, and I suppose I could try one or all of the following to resolve this?:

1) increase fueling in this hz range but then I'd have to 0 out the PE fuel, which in the end would cause all kinds of other problems I would think.

2) Enter WOT slower, but that can be tricky

3) Would it be possible to delay the reaction of the Throttle blade just a bit by software so no matter how fast I mat the throttle, it's opening rate is slowed just a bit to take care of this problem?

4) increase the about of burst knock during very rapid WOT throttle transitions without affecting normal (non-WOT shifting) burst knock amounts? If I find a way to add up to 10 degrees of Burst Knock timing reduction in this type of throttle change then this problem would likely not exist.

[10_SS]

Anybody have any input on this?

I looked around and found the E38 is known for a slower MAP sensor response.. which looks like the root of my problem,

But, my stock NA "Stomp Base Gain" type fuel calc's are 0's much different than the ZL1 settings, but they also have different fuel setup, and most other NA engines also have 0's in this table.

For whatever reason the MAP reading is slow to reference boost, which delays PE enrichment, but once PE is enabled the "Commanded AFR" drops to 10.8AFR, then things are fine.

So really only one problem: delay'd MAP response which causes a delay entering PE fueling causing a lean condition between shifts when the pedal is mashed fairly quick.

The MAF, Throttle, 02's, etc all update instantly, it's just the MAP therefore PE fueling that take a bit too long to react.

Are the ZL1 Stomp settings populated to take care of the problem I'm having? Possibly?

[10_SS]

ARF Commanded is 14.68ARF at 189kPa on the way to 211kpa. (Tune says to enable PE at 89kPa and 2% TPS).

ARF Commanded showing 14.68AFR

PE is now ON, but still Commanding 14.68AFR. PE was OFF at 101kpa. (Tune says to enable PE at 89kPa and 2% TPS)

Yea... there's no PE delay.. it's just really sluggish?


..

[ingsteve]

It srems the same problem of the other post with pe delay with new beta. PE cannot be controlled as we want...

[DSteck]

You are aware of why MAF only operation causes a lean condition on hard throttle changes, right? Especially with a PD blower... It's "reacting" to the air rushing into the blower housing. That doesn't mean the air simultaneously rushes into the cylinders.

[IDRIVEAG8GT]

The E38's are just hateful little brutes when it comes to this. The only thing I have found to be able to take care of this is to increase the Transient Base Multiplier by a ton. The E38 just doesn't react quickly enough to rapid throttle changes.

[DSteck]

Yes it does. You just need your VE dialed in well. The E38 responds exponentially faster than the 0411s.

[98S10]

The E38's are just hateful little brutes when it comes to this. The only thing I have found to be able to take care of this is to increase the Transient Base Multiplier by a ton. The E38 just doesn't react quickly enough to rapid throttle changes.

Are you ever ever gonna be quiet as a student should and let the adults talk? And sit back and learn how an internal combustion engine and ecm work together?

[10_SS]

IDRIVEAG8GT, can you post a general range of what you noticed an improvement with? I started adding here, but only 10%
"The only thing I have found to be able to take care of this is to increase the Transient Base Multiplier by a ton."

People, the stock ZL1 datalogs show the same PE delay, LEAN 02's while shifting under boost, and the resultant KNOCK so... what about operator error? How about you tell us exactly what to enter to stop PE delay, stock lean shifting and knock... but I don't think you can do that or you already would have.

Attached are TWO pictures of the ZL1 datalog showing PE DELAY, LEAN 02's while shifting under boost, and the resultant KNOCK due to this.. the problem is I don't have the config file to show all the parameters, but you can see it was during a shift, just like ME, and his 02's are LOW while he's well into boost. The first pic is at ~118kpa, lean as heck, on the way to 128kpa and 6 degrees of KNOCK, and still lean has heck but getting better.. also watch the INJECTOR pulswidth slowly increase, what you dont see is the log after peak knock the injector pulse is finally up to 17.5.. so LEAN LEAN LEAN transitions even from factory (with proper VE's for those that think that's all the problem is).

We would like to try to fix this from happening.. and not just argue and poke fun, because these are real problems that can be fixed, just need the software/settings to do it.

Wish I would have just bought an automatic!

[DSteck]

Are you ever ever gonna be quiet as a student should and let the adults talk? And sit back and learn how an internal combustion engine and ecm work together?

Lulz.







I've completely lost interest in helping. I am instead going to drink more beer.

[c.u]

Beer is good.You can not win them all dave.

[SSUte01]

Lulz.







I've completely lost interest in helping. I am instead going to drink more beer.

If there was a "like" button, I'd be pressing the shit out of it. Not because I don't like helping, but because you have to choose your battles and beer is hmmmm good!

[IDRIVEAG8GT]

Are you ever ever gonna be quiet as a student should and let the adults talk? And sit back and learn how an internal combustion engine and ecm work together?

STFU Noob.

[IDRIVEAG8GT]

Yes it does. You just need your VE dialed in well. The E38 responds exponentially faster than the 0411s.

Yeah? You think so eh Dave? You're wrong in the fact thinking that the VE isn't dialed in well.

I've done it NUMEROUS times now on 4 different FI setup E38's with rather large cams. All of them need an adjustment with transient fueling to compensate for instantaneous boost and/or rapid throttle transitions.

[DSteck]

Seems you've got it all figured out!

[IDRIVEAG8GT]

Seems you've got it all figured out!

No shit Sherlock.

[IDRIVEAG8GT]

I figure on a turbo car it's a lot different because of the spool time, and you can get away with stock transients and you're just sort of all motor in the meantime. Not to mention, large cams exaggerate this problem quite a bit.

[DSteck]

I've never done a large cammed PD blower car.



Hey, I can see the back of my skull!

[IDRIVEAG8GT]

+4* overlap or more starts making some bad issues with E38's. Of course the actual valve events have more to with it than anything, but that's just a rough representation. How fast a PD blower builds boost has more to do with it as well, considering a Magnacharger has a small delay between WOT and the time it takes to build boost as the actuator takes a bit to shut completely.





I bet you got picked on a lot as you were growing up.

[IDRIVEAG8GT]

IDRIVEAG8GT, can you post a general range of what you noticed an improvement with? I started adding here, but only 10%
"The only thing I have found to be able to take care of this is to increase the Transient Base Multiplier by a ton."

People, the stock ZL1 datalogs show the same PE delay, LEAN 02's while shifting under boost, and the resultant KNOCK so... what about operator error? How about you tell us exactly what to enter to stop PE delay, stock lean shifting and knock... but I don't think you can do that or you already would have.

Attached are TWO pictures of the ZL1 datalog showing PE DELAY, LEAN 02's while shifting under boost, and the resultant KNOCK due to this.. the problem is I don't have the config file to show all the parameters, but you can see it was during a shift, just like ME, and his 02's are LOW while he's well into boost. The first pic is at ~118kpa, lean as heck, on the way to 128kpa and 6 degrees of KNOCK, and still lean has heck but getting better.. also watch the INJECTOR pulswidth slowly increase, what you dont see is the log after peak knock the injector pulse is finally up to 17.5.. so LEAN LEAN LEAN transitions even from factory (with proper VE's for those that think that's all the problem is).

We would like to try to fix this from happening.. and not just argue and poke fun, because these are real problems that can be fixed, just need the software/settings to do it.

Wish I would have just bought an automatic!

Take the base gain multiplier under the transient tab. Highlight the entire table. Multiply by 1.90. That's the equivalent to 90% and could possibly be overkill but give it a try.